1. Field of the Invention
The present invention relates to a card type camera which is used in connection with an information processing device such as electronic notebooks or other portable information equipment, personal word processors, and personal computers.
2. Description of the Background Art
A conventional electronics still camera is disclosed in Japanese Patent Laid-Open Publication No. HEI 1-176168. FIGS. 1, 2, and 3 are a front view, a side view, and a circuit block diagram of the electronics still camera, respectively. The electronics still camera 1 comprises a card camera having an image input unit, which is composed of a lens 4 and a CCD (Charge-Coupled Device) 5, provided in the center of a card-like body 3 as shown in FIGS. 1 and 2. In connection with an exclusive-use reproducing section 2 (see FIG. 3) via connectors 6, the electronics still camera 1 reproduces still image information written in image-use memory.
Referring to FIG. 3, drive pulses are generated by a drive pulse generator 8 based on a timing signal derived from a synchronizing signal generator 7, whereby a drive signal for the CCD 5 is generated by a drive circuit 9. Then, an output signal from the CCD 5 is sampled by a sample hold circuit 10, gain-controlled by an AGC (Automatic Gain Control) compressor 11, and thereafter log-compressed. The log-compressed signal is converted into a digital signal by an A/D (Analog-to-Digital) converter 12, and then log-expanded by an expander 13. Further, it undergoes such processes as color separation, horizontal/vertical edge correction, .gamma.-correction, and white balance by a processor 14. R, G, and B signals obtained in this way are stored via a data buffer 15 into an image memory 16 composed of R memory, G memory, and B memory.
The R, G, and B signals thus stored in the image memory 16 are transmitted to the reproducing section 2 via the connectors 6. Then, they are converted into analog signals by a D/A (Digital-to-Analog) converter 17 of the reproducing section 2, and amplified by an image amplifier 18. Thus, a still image is displayed on a monitor 19 based on the amplified analog signals. Various types of image processing involved in this display process for the picked-up still image are executed by an unshown image processing unit on the reproducing section 2 side.
In the above-described electronics still camera 1, as shown in FIGS. 1 and 2, an image input unit composed of a lens 4 and a CCD 5 is provided in the center of the card-like body 3, while connectors 6 are provided on a side edge. Therefore, when the electronics still camera 1 is operated to pick up an image under real-time monitoring in connection with the exclusive-use reproducing section 2, the generally entire body 3 except the connectors 6 is projected from the reproducing section 2. This results in a poor convenience of use, as a problem.
Also in the electronics still camera 1, no special image processing is executed upon the R, G, and B signals that have been converted into digital form by the A/D converter 12 and stored in the image memory 16. Thus, various types of image processing, when executed upon the digitized R, G, and B signals, need to be done by the image processing unit on the reproducing section 2 side as described above. Therefore, it is necessary to allow a processing time before the picked-up image is reproduced. This poses another problem that the image cannot be captured under the real-time checking of the focusing state, or that the focusing adjustment cannot be attained manually. As still another problem, when the reproducing section has a display device incapable of multi-level halftone display, such as liquid crystal display devices, a high-grade image cannot be displayed directly.
Also in the electronics still camera 1, since hand moves may occur during the hand-hold photographing, only one-side field image signals out of the image signals derived from the CCD 5 can be used. This causes a problem that the vertical resolution deteriorates to one half. An FIT (Fail-In-Time) type CCD may be used to avoid such a problem, but this would result in a great increase in cost.
Also in the electronics still camera 1, when it is connected to the reproducing section 2, one-way access only from the electronics still camera 1 side is permitted. Therefore, the image memory 16 cannot be accessed from the reproducing section 2 side. As a result, it is impossible to read necessary image data stored in the image memory 16 from the reproducing section 2 side, execute image processing on them, and transfer the processing results to the electronics still camera 1 once again.
Further, the lens 4 is projected vertical to a direction in which the card-like body 3 extends. As a result, when the electronics still camera 1 is connected to the exclusive-use reproducing section 2, the direction of the subject relative to the direction of the display screen of the reproducing section 2 is limited naturally. This leads to a further problem that subjects in various directions cannot be photographed in a state that the display screen of the reproducing section 2 is set up to be easy to monitor.
Also in the electronics still camera 1, whereas image data of a subject is captured by pressing a shutter switch 20, the camera 1 is not provided with the function of producing a shutter sound at the press of the shutter switch 20. As a result, the operator cannot be sure that image data of the subject has been captured by an operation of the shutter switch.